1. Field of the Invention
This invention relates to a rail system for a robot and, more particularly, to a modular rail system which provides an auxiliary axis with a reconfigurable length for a plural axis robot.
2. Background of Information
In a manufacturing process using a robot, it is often necessary to increase the working envelope of the robot through the addition of one or more auxiliary axes. Typically, the auxiliary axis is a linear or longitudinal axis which is parallel with respect to a conveyor or workpiece associated with the robot. The length of a fixed, single piece longitudinal axis is generally limited by the available machine tools to about 12 meters.
In robotic painting applications, for example, it is known to provide an auxiliary axis for a plural axis robot in both "Clean Wall" and "In-Booth" configurations. The "Clean Wall" configuration includes a robot cantilevered from a base. A barrier or wall is positioned between the base and the robot which is located in a painting booth. In this manner, there is smooth air flow in the painting booth and minimal obstruction of the floor therein. Furthermore, the base is normally kept clean of paint overspray and is accessible from outside of the painting booth for service. The "In-Booth" configuration is a floor mounted unit with the robot mounted above the base. This configuration is typically used in retrofitting existing painting booths or when floor space is restricted.
U.S. Pat. No. 5,183,377 discloses a mounting and rail structure for an industrial robot including vertical support posts for longitudinal rail carriers which are interconnected at the end by transverse connectors. Four end elements each connect a rail carrier with a corresponding transverse connecting bar. A transverse movable rail has its two ends positioned in pocketlike uprights of two respective end elements. An object of U.S. Pat. No. 5,183,377 is to provide a rail system in such a manner that many parts are standardized in order that a variety of combinations and rail systems can be assembled from the many standardized parts.
In robotic painting applications, for example, relatively long auxiliary axes (e.g., greater than about 7.5 meters in length) are difficult to handle during both shipping and installation. In prior known rail systems, a relatively large number of different length components are required in order to provide a sufficient variety of auxiliary axis lengths which meet the needs of most applications.
There is a need, therefore, for a rail system for a robot which is easy to handle during shipment from the vendor to the user of the system.
There is also a need for a rail system for a robot which is easy to handle during installation of the system.
There is another need for a rail system for a robot which is easily reconfigured during modification of the system.
There is still another need for a rail system for a robot which reduces the inventory requirements of the vendor of the system.